Accumulator



Nov. 27, 1945. w. A. LIPPINCOTT AC CUMULATOR 2 Sheets-Sheet 2 Filed Oct. 25. 1945 NVELNTOk QJe/Xs O4), wp/hco A) flu/Lu MI Patented Nov. 27,1945

UNITED STATES PATENT OFFICE.

aoouuvmroa v well]; A. Iiippinoott, Evanston, 111., unmito Ideal Roller a Manufacturing Comm- Chicage, 111., a corporation of Illinois 1 Application October 25.1w, Serial No. 501,573

Claims. (01. res-so) element such as a coiled spring wire it may be This invention relates to hydraulic accumulators in which a bladder or diaphragm ofsynthetic rubber or the like is used to separate bodies or liquid and compressed air within a tank.

The invention aims to achieve high volumetric eillciency in such an accumulator by providing a novel means for insuring the escape during expension of the bladder oi. any liquid that may become trapped between the bladder and the tank wall.

The invention also resides in the novel strucaural character of the means for accomplishin ;he foregoing object.

Other objects and advantages of the invention vill become apparent from the following detailed lescription taken in connection with the accomianying drawings, in which Figure l is a transverse sectional view of an lccumulator embodying the novel features of the present invention.

Figs. 2 and 3 are fragmentary cross-section views taken along the line 2-2 of Fig. 1 under different operating conditions.

Fig. 4 is a view like Fig. 1 showing a diflerent operating condition.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein describe in detail the preferred embodiment. It is to be imderstood, however, that I do not intend to limit the invention by such disclosure but aim to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

In the drawings the invention is shown embodied in an accumulator comprising a rigid spherical tank 5 formed at one end with a flanged opening 6 constituting a fluid inlet and outlet and at the other end with a flange 1 defining an open ing through which a flexible bladder or diaphragm 8 may be inserted. In this instance, the bag comprises two hemispherical cups 9 and I0 molded of resiliently yieldable material such as synthetic rubber which remains relatively flexible at low temperatures. The cup 9, which flexes into and out 01' the cup Iii as liquid flows into and out of the opening 6 is made somewhat mor flexible than the cup Ill, and, in the construction shown in Fig. 1, the latter is shaped to fit closely within one end of the tank. Preferably, the cup I0 is somewhat shallower than a true hemisphere, and its lip II is overlapped by the feathered lip I2 01' the cup 9 which latter lip tapers to a feather edge and is adhesively secured around the lip II. I! desired, a resilient extensible and contractible molded into" the lip l I to insure expansion of the latter against the tank automatically following insertion of the bladder through the flange 1.

The cup ll may be secured directly to a valve stem and thereby supported within the tank. Or,

as in the present instance. it may have an opening defined by a neck H which may be clamped around the tank opening in any suitable way. Herein, the neck is turned outwardly around a bead II which provides a shoulder against which a flange it on the neck is clamped by a cover It, the clamping pressure being applied by a ring l9 threading into the flange I. The bladder is inflated by air introduced through a valve stem 20 on the cover.

Bladders oi the above character stretch both radially and longitudinally oi the cup axis when inflated. If as shown in Fig. 1, the cup Iii is molded to flt the interior of the tank, the stretching of this cup will be only longitudinal as the bladder expands fully within, the tank. As an incident to this, the lip II will shift toward orbeyond the tank center. 0n the other hand, the cup I 0 may not be formed to flt accurately within the tank end. In such a case, part or the cup may be separated irom the internal surface of the tank leaving, for example, a space 24 as shown in Fig. 4. An an incident to full expansion of such a bladder, the cup I0 is expanded radially.

In either of the instances referred to above,

the wall of. the cup I0 is tensioned or extended in an edgewise direction. Advantage is'taken 01' such stressing to provide against the entrapment of fiuid between the tank wall and the cup in while the bladder'is expanding during the discharge of the fluid from the accumulator. Accordingly, the invention contemplates the provision of means which, as an incident to such stretching of the cup Ill, forms channels between the exterior of this cup and the interior of the tank, such channels extending toward the tank outlet 8 so as to permit trapped fluid'to escape along the tank wall and pass the lips of the cups. Herein, this means comprises annularly spaced ribs or thickened portions 2i molded on the inside of the cup Ill and extending longitudinally of the latter from points adjacent the neck l4 to'points near the lip ii.

Owing to their greater thickness, the sections 2| will resist stretching more than the thinner intervening portions gf. the cup i0. Thus, as the wall of this cup stretches during inflation oi. the bladder, the thickened parts 2| of the bladder shown in Fig. 1 straighten out and move awayiromthetankwallasshowninl'iat. Inthecaseofthebladder showninl'ig. 4, the

thinner areas expand against the tank while the thickened parts remain spaced therefrom. As a result, external meridian channels 22 are created temporarily opposite the thickened portions II, and the liquid trapped in any pockets between the cup II and the tank wall collects in these channels and is permitted to flow therealong toward the outlet of the tank. If desired, knobs 23 may be molded or otherwise formed at annularly spaced points around the exterior of the cup lip l2, these serving to provide adjacent channels for the escape of oil from the channels 22 into the space between the cup 9 and the tank.

I claim as my invention:

1. An accumulator having, in combination, a spherical tank, and a similarly shaped bladder supported at one end by the tank so that the adjacent portion is stretched as an incident to full expansion of the bladder within the tank, said flrst mentioned portion only having alternate thick and thinareas annularly spaced and differently stretched during said expansion whereby to create meridian channels for the escape of fluid becoming trapped between the tank and said first mentioned portion.

2. An accumulator having, in combination, a spherical tank, and a similarly shaped bladder therein secured at one end to the tank with the adjacent semi-spherical portion fitting closely within one end of the tank to permit flexing of the remaining portion of the bladder into and out of said flrst portion, said first portion being thickened on the inner side thereof and along annularly spaced longitudinal lines to form annuiarly spaced thin wall areas separated by thickened areas which stretch to a lesser degree than said thin areas whereby to form external channels permitting the escape of any liquid trapped between said portion and the internal wall of the, tank.

3. An accumulator having, in combination, a spherical tank, a bladder in said tank having a semi-spherical end portion which when deflated is substantially the same size as the interior of said tank, the-other end portion of the bladder when deflated being somewhat shorter axially than the first portion, means securing said first mentioned end portion to said tank, and meridian ribs formed on the interior of said flrst mentioned spherical portion and operating during inflation of the bladder to create fluid escape channels disposed between the interior of the tank and the xterior of said first end portion.

4. An accumulator diaphragm comprising a flexible walled bag having a smooth external surface and adapted to be inflated by introducing air in one end, and annularly spaced meridian ribs formed on the interior of said bag and extending from said end substantially to the equator of .the bag, the inner and outer wall surfaces of the remaining portion of the bag between said ribs being smooth.

5. An accumulator diaphragm comprising a flexible walled bag having a smooth external surface and adapted to be inflated by introducing air in one end, annularly spaced meridian ribs formed on the interior of said bag and extending from said end substantially to the equator of the bag, and projections on the exterior of said bag spaced around the equator thereof.

WELLS A. LIPPINCOTI. 

